Concrete-pile form.



J. R. SELFRIDGE.

CONCRETE PILE FORM.

APPLICATION FILED JULY 6, 1915.

1,163,377. Patented Dec. 7, 1915.

INVENTQR.

J 7?. SE'ZJPRJUGE Q5 4manm, BY m w ATTORNEYS.

WITNESSES JAMES R. SELFRIDGE, OF SAN FRANCISCO, CALIFORNIA, l ASSIGNOR,TO SELFRIDGE HOLDING COMPANY, OF SAN FRANCISCO, CALIFORNIA, ACORPORATION 013 CALI- FORNIA.

CONCRETE-FILE FORM.

Application filed .1 uly 6, 1915.

To all whom it may concern:

Be it known that I, JAMES R. Snnrnmcn, a citizen of the United States,and a resident of the city and county of San Francisco, State ofCalifornia, have invented a certain new and useful Concrete-Pile 'Form,of which the following is a specification.

The invention relates to forms for the manufacture of concrete piles.

An object of the invention is to provide a cheap and efficient form forconcrete piles.

The invention possesses other advanta- V eous features, which, with theforegoing, will e set forth at length in the following description,where I shall outline in full the preferred form of construction which Ihave selected for illustration in the drawings accompanying and formingpart of the present specification. From this it will be ,Iunderstoodthat I do not limit myself to the showing made by said drawings anddescription, as I may adopt many variations within the scope of myinvention as set. forth in the claims succeeding the description.

Referring to said drawings: Figure 1 is a vertical section of a concretepile constructed in accordance withmy invention. Fig. 2 is a crosssection of the pile.

Heretofore, in the construction of concrete piles, the cost of the formhas been a material factor and difiiculty has been encountered inremoving the pile from the form after the concrete has set. The cost ofmetal forms is so great that it isimpractical to provide a new form foreach pile and to allow the form to remain on the pile and wooden formsmust be removed before the,

pile can bedriven. In accordance with my invention I provide a formwhich is sufiiciently cheap,'so that a new form may be used for eachpile and the form allowed to remain on the finished pile when desired.

The form of my invention consists of a spirally wound paper tube 2,suitably waterproofed, so that it will not-absorb moisture from theconcrete 3 of which the pile is formed. The spirally wound paper tube isarranged vertically and engages at its bottom a conical metallic shoe 4,which forms the driving point of the pile, the shoe being provided witha circumferential shoulder 5 on which the tube sets. Cast or otherwisesecured in the shoe, are a plurality of anchor Specification of LettersPatent.

Patented at... a, was. Serial No. 33,095.

tube adjacent its upper end, the tube being provided with reinforcement12 at the point at which the pipe passes through. When the pile is beingdriven, water is forced through the pipe 9 to loosen the earth inadvance of the pile. A metallic cap 13 is also placed on the top of thepile during driving, to receive the hammer blows.

The spirally wound paper tube provides a cheap and efficient form, whichmay be allowed to remain on the pile after it has been cast and as it isdriven. This method of construction obviates the expense and timenecessary to remove the form from the pile after it is finished andeliminates the fuse of expensive forms, which must be removed from thepile.

I claim:

1. A form for a concrete pile comprising a- .spirally wound paper tubeand a metallic shoe arranged at the lower end of and closing said tube.

2. A form for a concrete pile, comprising a. spirally wound paper tube,and a metallic shoe arranged at the lower end of said tube.

3. A form for a concrete pile comprising a spirally wound paper tube, ametallic shoe arranged at the lower end of said tube, a conduitextending through said shoe into said tube and through the side of saidtube adjacent the upper end thereof and reinforcing means attached tothe tube and surrounding' the aperture through which the conduit passes.

4. A form for a concrete pile comprising a conical metallic shoeprovided with a circumferential shoulder, and a spirally wound papertube seated on said shoulder.

In testimony whereof, I have hereunto set my hand at San Francisco,California, this 23rd day of June 1915.

- JAMES R. SELFRIDGE.

In presence of- H. G. Pn'os'r.

